Bag closing machine and control means therefor



R. l.. WING 3,001,341

4 Sheets-Sheet 1 A TTOHNEY Sept. 26, 1961 BAG CLOSING MACHINE ANDCONTROL MEANS THEREFOR Filed Dec. 17, 1959 sept. 26, 1961 LV1/m@3,001,341

BAG CLOSING MACHINE AND CONTROL MEANS THEREFOR Filed Deo. 1'7, 1959 4sheets-shet 2 INI/ENTOR. Ra/p L. Wing f @www ATTORNEY Sept. 26, 1961 R.L. WING 3,001,341

BAG CLOSING MACHINE AND CONTROL MEANS THEREFOR Filed DSG. 17, 1959 4Sheets-Sheet 3 l JNVENTOR. f90/ph L. W/'ng BY @MdL/.M

A TTHNEY R. L. WING Sept. 26, 1961 BAG CLOSING MACHINE AND CONTROL MEANSTHEREF'OR 4 Sheets-Sheet 4 Filed Dec. 17. 1959 Pfg? JNVENTOR. /a/ph L.Wing BY mawem( United States Patent 3,001,341 BAG CLOSING MACHINE ANDCNTRL MEANS THEREFUR Ralph L. Wing, Burlington, Mass., assigner toPneumatic Scale Corporation, Limited, Quincy, Mass., a corporation ofMassachusetts i Filed Dec. 17, 1959, Ser. No. 860,116

14 Claims. (Cl. 53-76) This invention relates to a bag closing machine.

The invention has for an object .to provide a novel and improved machinehaving provision for closing the extended mouth portion of a bagcontaining an article and which is characterized by novel control meansadapted to discontinue operation of the machine in the event that thearticle is improperly positioned within the bag or the filled bagmisaligned with respect to the bag closing mechanism to prevent damageto the article during the mouth closing and sealing operation and toenable an attractive, ecient mouth closure to be made.

. The invention has for another object to provide a novel and improvedcontrol means particularly adapted for use in a machine wherein a flatbag containing an article of merchandise is engaged at its mouth portionbetween opposed belts to be gripped and advanced into operative relationto mouth closing mechanism and which is characterized by its ability todetect relatively small abnormal separation of the belts and todiscontinue operation of the machine in the event that a relatively thinmisaligned portion of the merchandise is received between the belts.

With these general objects in View and such others as may hereinafterappear, the invention consists in the bag closing machine and in thecontrol means as hereinafter described and particularly del-ined in theclaims Vat the end of this specification. A

In the drawings illustrating the preferred embodiment of the invention:

FIG, l is a front elevation of a bag closing machine herein shown as abag trimming and sealing machine embodying the present invention;

`FIG. 2 is a` plan view of a portion of the machine shown in FIG. l; g

g FIG. 3 is 'a side elevation detail view of the detecting mechanismforming a part of the control means, some of the parts being shownincross section; i

FIG. 4 is a view similar to FIG. 3 showing the parts in a differentposition of operation;`

FIG. 5 is a front elevation detail View of the detecting mechanism;

FIG. 6 is a vertical cross section of thedetectingrnechanism taken onthe line 6 6 of FIG. 5 and FIG. 7 `is a wiring diagram illustrating thecontrol circircuit for discontinuing operation of the machine inresponse to the detecting mechanism.

In general the present invention comprises an improvement in the bagtrimming and sealing machine illustrated and described in a copendingapplication, Serial No. 699,630, by Robert W. Saumsiegle, for Method andApparatus for Trimming and Sealing Plastic Bags, filed November 29,1957, and asigned to applicants assignee.

In the operation of the trimming and sealing machine disclosed in theSaumsiegleapplication, above referred to, a ilat ybag of thermoplasticmaterial open at the mouth and containing an article of merchandise isplaced on a conveyer with the open mouth portion extended laterally overone side thereof. The mouth portion is then engaged by opposedcontinuously moving gripping elements in the form of upper and lowermetal belts or bands arranged to clamp the walls of the mouth portiontogether along a line spaced a relatively short distance from the edgeof the merchandise contained in the bag, leaving a substantial portionof the'mouth extended beyond the tance from the metal belts.

ln practice it was found that through inadvertence the article might beimproperly positioned within the bag and a portion of the merchandisemight extend into the mouth portion of the bag, or the bag might bemisaligned in a manner such that the opposed belts :would grip a portionof the merchandise therebetween and as a result when the bag wasadvanced to the hot wire the latter would effect burning of themerchandise or an improper closure effected.

yIn accordance with the present invention provision is made fordetecting misalignment of the merchandise in the bag or of the bagrelative to the opposed belts carrying the bags to the trimming andsealing mechanism and for discontinuing operation of the machine in theevent that a portion of the merchandise contained in the bag is receivedbetween the belts so that the operator may realign and properly positionthe bag and the merchandise whereby to avoid damage thereto or to thetrimming and sealing mechanism. ln practice the present control means iscapable of detecting a relatively minute separation of the belts beyondIthe normal separation, as dictated by the thickness of the mouthportion of the bag, whereby to detect even relatively thin Vportions ofthe merchandise within the bag which are inadvertently presented betweenthe belts, the control means including means responsive to the detectingmeans for discontinuing operation of the machine.

Referring now to the drawings, in general the bag trimming and sealingmachine embodying the present invention may comprise the machineillustrated and described in the Saumsiegle application, `above referredto, and only such portions of the machine essential to an understandingof the present invention will be herein described. .As hereinillustrated, in the operation of the bag trimming and scaling machine a4ilat bag 12 of thermoplastic material containing an article ofmerchandise 1l is placed horizontally on a conveyor belt 10 with theopen mouth portion 14 extended laterally beyond one edge of the belt topresent the extended mouth portion in alignment with the trimming andsealing mechanism. The conveyer belt lll may be continuously driven-inany usual or preferred manner, not shown, and the mouth portion 14 ofeach bag is rst engaged by opposed upper and lower flat belts lo, l forthe purpose of bringing the opposed walls of the mouth together insubstantially flat face-to-face contactlng engagement. Ilhe ilattenedmouth portion is then presented between opposed upper and lower metalbelts 20, 22 which are preferably arranged Eat an angle with relation toeach other and with relation to the horizontal plane of the mouthportion of the bag so that the contacting edges of the belts 20, 22cooperate to engage the mouth along a relatively narrow line of contact.While thus gripped between the metal belts, the mouth portion isadvanced into engagement with a heated wire 24 to effect trimming of theextended portion of the mouth land sealing ofthe mouth by liqueiicationand fusion of the plastic bag material. lAs illustrated in FIG. 1, thewire 24 may extend longitudinally between spaced, upright posts 70, 172and is preferably arranged at a small angle relative to the horizontalplane of the mouth portion gripped between the metal belts or bands. Themouths of the bags may be initially aligned against an adjustable stopor guide member 26 to present the mouth portion between the mouthengaging belts and to present the extended portion of the mouth in thepath of the heated wire 24.

The'opposed upper and lower belts 16, 18 may comprise relatively narrow,flat and longitudinally` extended endless belts, the upper belt 16 beingarranged to run over end pulleys 28, 30 carried on shafts 32, 34, andthe lower belt 18 being arranged to run over end pulleys 36, 38 carriedby shafts 40, 42. The pulleys 28, 36 may comprise drive pulleys fast on-their respective shafts 32, 40 and connected to rotate in oppositedirections by spur gears 44, 46, the idler pulleys 30, 38 being mountedto rotate on their respective shafts 34, 42. The shafts 32, 34 and 40,42 are carried by and extended from diverging arms 48, 50 at each end ofa horizontally extended bracket 52.

The belts 16, 18 may comprise leather or like material possessingsufficient rigidity to press the opposed walls of the mouth portion ofthe bag or container in at contacting relation, as described, andprovision is made for driving the belts at a linear speed equal to thespeed of advance of the bags on the conveyor through driving mechanismshown in FIG. l. The driving mechanism includes a driving motor 84connected through a speed reducer 86 to a bevel gear 88 on a shaft 90 inmesh with a bevel gear 92 on a shaft 94. The shaft 94 is provided with apulley 96 connected by a belt 98 to a pulley 100 fast on the lower drivepulley shaft 40 which is connected to the upper drive shaft 32 by thespur gears 44, 46 as described.

After the mouth portion 14 ofthe container is closed by the belts 16,18, the attened mouth is received between the angularly arranged upperand lower metal belts 20, 22. As illustrated in FIG. 1, the metal beltsinitially engage the mouth portion at a point intermediate the length ofthe engaging run of the mouth flattening belts 16, 18 so that both setsof belts are in engagement with the mouth portion `for the remaininglength of the run of the belts 16, 18. The metal belts 20, 22 extendbeyond the flattening belts, as shown, so that when the bag mouth issubsequently engaged by the heated Wire 24 it will be gripped betweenthe metal belts only.

As herein illustrated, each metal belt is disposed at an angle of about45 with respect to the horizontal plane of the mouth portion of the bagand at an angle of about 90 with respect to each other, so that theupper and lower faces of the mouth portion are engaged by thecooperating edges of the upper and lower metal belts 20, 22,respectively, the upper and lower belts being preferably olfset relativeto each other so that the thin or narrow edge of one belt may engage themarginal edge of the wide face of its cooperating belt. The metal belts20, 22, are arranged to run over upper and lower pulleys 104, 106 and108, 110, respectively, which are mounted on axes arranged at an angleof 45 as shown. The belts 20, 22 are also arranged to travel atA alinear speed equal to the advance of the containers on the belt 10 and,as herein shown, the drive pulleys 104, 108 are mounted fast on shafts112, 114, respectively, journaled in brackets 115 carried by the wall116 of a frame member 118. Each shaft 112, 114 is provided with a wormgear v120, 122, each of which-is in mesh with a worm 124 fast on a shaft126 journaled in a bearing member 128 secured to the wall 116 of theframe. The worm 124 is arranged to be rotated through connectionsincluding a chain and sprocket drive`130 between the shaft 126 and theoutput shaft of a speed increasing unit 132. A second chainy andsprocket drive 136 connects the input shaft of the speed increasing unitto a drive shaft 138. The drive shaft 138l is provided with a bevel gear140 in mesh with the bevel gear 92 forming a part of the main drivemechanism as described. The upper and lower pulleys 106, 110 which arealso mounted on axes arranged at 4an angle of 45 as shown, are arrangedto rotate on shafts 142, 144, respectively, which are journaled inbrackets 146, 148 attached to a second wall 150 of the frame member 118.l

From the description thus far it will be observed that successive bagsplaced on the conveyor 10 and aligned with the guide member 26 areadvanced to present the unsealed mouth portions thereof between theopposed upper and lower mouth attening and closing belts 16, 18, andwhile thus held and advanced the mouth portions are engaged betweenopposed upper and lower angularly arranged metal belts 20, 22 along aline spaced a short distance inwardly of the outer margin of the mouthportion and inwardly relative to the line of engagement of theliattening belts. Thereafter, when the bag mouth leaves the belts 16, 18and is only gripped between the extended portions of the metal belts 20,22, the leading edge of the bag mouth is advanced into intersectingengagement with the heated wire 24 to effect the trimming and sealingoperation.

As illustrated in FIGS. 1 and 2, the present control means includesdetecting mechanism indicated generally at 300 which is disposedadjacent the receiving end of the metal belts 20, 22 at a point spaced ashort distance forwardly from the vertical center line of the pulleys106, 110. As shown in detail in FIGS. 3 and 4, the detecting mechanism300 is mounted at an angle of about from the Vertical and at rightangles to the upper angularly arranged metal belt 20 with which thedetecting mechanism is designed to cooperate. The detecting mechanismincludes a contact member in the form of a pointed metal member orneedle 302 carried by and replaceably secured in a conducting bar 304 bya set screw 305 as shown in FIG. 5. The conducting bar 304' is attachedto and insulated from a holder 306 pivotally mounted on a shoulder stud308 secured to a supporting plate 310. The plate 310 is attached bybolts 312 to a block 314 extended fromand secured to a portion of thepulley bracket 146 by bolts 316.

As. illustrated in cross section in FIG. 6, the shoulder stud 308isprovided with upper and lower bronze washers 318 to assure :free pivotalmovement of the holder 306, and an angularly extended arm 320 of theholder is provided with an adjustable set screw 322 for cooperation witha stop block 324 secured to the supporting plate by bolts 325. A coilspring 326 connected between the arm 320 and the block is arranged torock the holder in a counterclockwise direction to present the end ofthe contact needle 302 in spaced relation to the upper metal belt 20,the set screw 322 being adjusted .to vary the spacing between thecontact needle and the belt. The Vset screw 322 may be locked in itsadjusted position by a nut 323.

As illustrated in FIG. 6, the conducting bar 304 which carries thecontact needle 302 at one end is insulated from the holder 306 by anintervening insulating strip 328, and the metal screws 330 securing thebar to the holder eittend through insulating bushings 332. As shown inFIG. 5, the other end of the conducting bar 304 is provided with a lead334 forming a part ofv a 6-volt circuit 336 grounded through the machineframe as indicated at 338, 340 in FIG. 7. The circuit 336 includes afuse 342 and a control relay 344 arranged to open the motor circuit 346when the relay circuit 336 is closed by engagement of the metal belt 20with the contact needle 302.

In the normal operation of the machine whenv the mouth portions of the`flat thermoplastic bags Vor containers 12 containing mechandise, such asa cloth garment, are received between the metal belts 20, 22, normalseparation of the belts equal to the thickness of opposed walls of thebag is not suicientto effect movement of the upper belt 20 intoengagement with the contact needle 302, the spacing of the needle beingillustrated in FIG. 3. However, in the event that the bag is misalignedor the mechandise in the bag is not properly positioned therein suchthat an edge of the mechandise is received between the belts, as shownin FIG. 4, the belts will be abnormally spread apart and the upper belt20 moved into engagement with the contact needle 302, Vthus closing thecircuit to the relay 344 and opening the motor circuit 346 todiscontinue operation of the machine. Engagement of the belt 20 with thecontact needle may es eirect rocking of the contact unit in a clockwisedirection, the extent of such movement depending on the thickness of themechandise engaged between the belts. Upon removal of the abnormally orimproperly positioned bag, or proper positioning thereof, the beltsreturn to their normal position, and the contact unit is returned to itsinitially adjusted position by virtue of the spring 326 to again permitthe continuous operation of the machine, the motor circuit 346 beingclosed uponY removal of the contact 302 from contact with the belt 20.

In operation the contact needle 302 is preferably adjusted relative tothe metal belt 20 by movement of the set screw 322 such as to provide aminimum clearance space between the belt 20 and the end of the needle302 when the mouth portion of a properly lilled and positioned containeris aligned between the belts 20, 22. In practice the amount of clearancefor normal operation of the machine may be in the order of fourthousandths of an inch, such that the end of needle 302 just aviodscontact with the belt whereby a minute increase in the spacing of thebelts 20, 22 causes the needle to contact the belt 20 and discontinueoperation of the machine.

From the above description of the bag closing machine, herein shown as abag mouth trimming and sealing machine, it will be seen that the presentcontrol means provides `a safety device having an extremely sensitivedetecting mechanism adapted to discontinue operation of the machine inthe event that a slightly greater than normal separation of the metalgripping and conveying belts 20, 22 occurs, whereby to preventadvancement of a misaligned or improperly filled bag into operativerelation to the trimming and sealing mechanism and to thus avoid damageto the merchandise, such as burning the same by its engagement with thehot sealing wire or to the trimming and sealing mechanism, and also toprevent the formation of unattractive or defective seals.

While the illustrated embodiment of the invention contemplates closingof a grounded relay circuit upon detection of abnormal separation of thebelts to open the driving motor circuit, it will be apparent that thepresent control means may be used with advantage in a machine whereinthe gripping and conveying belts are of a nonconductive material andwherein abnormal separation of the belts may rock the contact unit toactuate a switch to effect closing of a conventional non-grounded relaycircuit whereby to open the motor circuit and discontinue operation ofthe machine. lIt will also be understood that the gripping belts neednot be angularly disposed, as illustrated herein, but may be arranged inparallel planes and in facetoface engagement.

While the preferred embodiment of the invention has been hereinillustrated and described as being embodied in a bag closing machineadapted for closing, sealing and trimming the mouth portions ofcontainers formed of a thermoplastic material, it will be understoodthat the invention may be embodied in other types of machines forclosing the mouth portions of various types of containers and fordetecting the position of the container and/ or the articles within thecontainer relative to the closing mechanism whereby to avoid damage tothe articles during the sealing operation and to assure the formation ofattractive, efficient closures or seals.

Having thus defined the invention, what is claimed is:

1. In a machine of the character described, in combination, means forclosing the mouth portion of a container containing an article ofmerchandise, means engageable with the mouth portion for gripping andadvancing containers into operative relation to said closing means, andcontrol means cooperating with said mouth gripping and advancing meansadapted to discontinue the operation of the machine in the event that aportion of the container and merchandise is engaged by said gripping andadvancing means.

2. In a machine of the character described, in combination, means forclosing the mouth portion of a container containing `an articleofmerchandise, a pair of opposed driven belts engageable with the mouthportion of the container for gripping and advancing the container intooperative relation to said closing means, and control means cooperatingwith said mouth engaging belts adapted to discontinue the operation ofthe machine in the event that a portion of the merchandise is grippedbetween said belts.

3. In a machine of the character described, in combination, means foradvancing a container having an article of merchandise therein through apredetermined path, said means including a pair of opposed driven beltsbetween which a portion of the container is gripped, and control meansactuated by abnormal separation of the opposed driven belts adapted todiscontinue operation of the machine when a portion of the article inthe container is received between the belts.

4. Control means as defined in claim 3 including the detecting meansnormally spaced a minute distance from one of said belts whereby todiscontinue operation of the machine upon relatively slight movement ofone of the belts into engagement with the detecting means.

5. VIn a machine of the character described, in combination, means forclosing the extended mouth portion of a bag containing an article ofmerchandise, means for supporting and advancing the bag into operativerelation Yto said closing means including a pair of opposed driven belts`between which the extended mouth portion of the bag is gripped, andcontrol means including detecting means cooperating with said beltsarranged to detect abnormal separation thereof, and means responsive tosaid detecting means for discontinuing operation of the machine when aportion of the merchandise in the bag is received between the belts.

6. In a machine of the character described, means for supporting andadvancing a bag having an open mouth portion and containing an article,said means including a pair of opposed driven members between which themouth portion is gripped, and electrical control means including acontact member cooperating with and normally spaced from said opposeddriven members arranged to detect `abnormal separation thereof, andmeans responsive to engagement of said contact member by at least one ofsaid driven members for discontinuing operation of the machine when aportion of the bag containing the article is received between saiddriven members separating the same abnormally. l i

7. Control means as delined in claim 6 wherein the opposed drivenmembers comprise electrically conductive -belts and form part of a relaycircuit arranged to be closed when at least one of the belts engages thecontact member to discontinue operation of the machine.

8. In a machine of the character described, in combination, means forsupporting and advancing a flat bag of relatively thin material havingan open mouth portion and containing at least one article ofmerchandise, said means including a pair of opposed, relatively thinmetal bands between which the mouth portion of the bag is gripped, andcontrol means comprising detecting means including a contact memberarranged to be engaged upon abnormal separation of the gripping bands,and means responsive to said detecting means adapted to discontinueoperation of the machine when any portion of the merchandise yin the bagis received between the bands, said contact member being normally spacedfrom the bands a relatively small distance in the order of a fewthousandths of an inch whereby to assure detection of a minute abnormalseparation of the belts due to the reception of any portion of thearticle of merchandise in the bag between the bands.

9. In a machine of the character described, a frame, means supported inthe frame for advancing a bag having an open mouth portion andcontaining an article of 7 mouth portion is gripped, means for drivingsaid belts including a motor having a circuit, and electrical controlmeans including a relay circuit grounded through said frame and saidbelts and arranged to control said motor circuit, said relay circuithaving -a contact member insulated from the frame, said contact memberbeing normally spaced from and arranged to be engaged by one of saidbelts to close said relay circuit to eiect opening of said motor circuitand discontinue operation of the machine upon abnormal separation of thebelts by the merchandise and engagement of the contact by at least oneof the belts.

10. Control means as defined in claim 9 wherein the contact member ismounted for pivotal movement when engaged by said one belt to compensatefor the amount of separation of the belts caused by the thickness of themerchandise between the belts.

11. vControl means as deiined in claim 9 wherein the relay circuitcomprises a low voltage circuit and the contact member includes acontact needle arranged to engage said one belt.

12. Control means as definedin claim 9 wherein the contact memberincludes a contact needle mounted for pivotal movement when engaged bysaid one belt, and means for adjusting the normal spacing between thebelt and the needle.

13. In a machine of the character described, container advancing meansengageable with a normally article free portion of a container providedwith an article of merchandise, said advancing means` being adapted toad- Vance the container through a predetermined path to be sealed, andcontrol means adapted to discontinue operation of the machine to avoiddamage to the article in the container by the sealing means, saidcontrol means being actuated by the engagement of the containeradvancing means with the control means when a portion of the articleextends into the normallyarticle free portion of the containercontaining the article of merchandise.

14. In a machine of the character described, in combination, meansengageable with an article free portion of a container for `advancing acontainer containing an article of merchandise through a predeterminedpath, and control means including detecting means adapted to cooperatewith said advancing means to detect the position of an article ofmerchandise improperly positioned within the normally article freeportion of the container and adapted to discontinue operation of themachine in the event the article of merchandise is detected to beimproperly positioned within the container.

References Cited in the file of this patent UNITED STATES PATENTS1,689,428 Farmer Oct. 30, 1928 2,715,807 Irmscher Aug. 23, 1955v2,797,793 Wilde et al July 2, 1957 ravi.)

